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Qsx15 turbo wastegate control valve? - Moffat - 10-31-2024
I’ve got a qsx15 cm570 s/n79165811 cpl8761in a case tractor stx480 with some issues I’ve been struggling with for a few years. It’s low on power and not smooth power curve. Will hang around25psi boost for most of the time but over a certain load it’s like it fuels hard and hits 35ish. More noticeable powerband issue when rpm’s are higher. I’ve set valves and injectors. Set base timing to 4 and 6 as per spec. replaced all fuel and metering actuators(fixed a rough cold start. Replaced Intake pressure and temperature multisensor. Replaced Barometric pressure sensor. Cleaned hexagon fuel screen and smaller fuel screen above hex screen. Blown back in fuel lines. Changed wastegate actuator(diaphragm was leaking). Had a retune to set it to an stx500. Tried a {garbage-can tuning box}(with it, it boosts to 38). changed wasegate hose. Had Cummins out and they say fuel pressures are good and no codes.
Only way to get it to boost smooth is to clamp off the hose between wastegate and wastegate controller but it still doesn’t seem to pull as good as it should. We have 3 other similar tractors 535 quadtracs s/n79418748 cpl 3087 and none of them act the same as this one. Pull much harder and smoother power. They don’t use a wasegate controller though they have cummins turbos whereas the 480 uses a holset turbo
Looking for any ideas what else to try on this thing. Or any insite to how the wastegate control valve actually functions or why it would make the turbo and or fueling smoother with the hose crimped. Also wondering if I could put the 535 tune and turbo on and just ditch the wastegate control valve altogether
RE: Qsx15 turbo wastegate control valve? - Rawze - 11-01-2024
first of all, you need the get that engine killing garbage can tuning box off that engine!. Also that CM570 only needs about 36 psi boost MAX! to make full power, and anything more will cause its premature demise!.
NEXT, it needs to be set back 100% factory spec and then put the program in it that belongs in it according to the vehicle specs and ser# for the engine... and stop lolly-gagging it to back-woods redneck death!.
After that, you need to put it on an actual dyno to get a proper base-line and see if the power output actually matches the programming, instead of guessing and d$icking around with 'how you feel' its doing instead of actually seeing what it is doing properly!.
- and if it is being help back.. STOP GUESSING !!!! AND MONITOR THE 'CBL_Fueling_State' / 'FSFNFLST' (what circuit is controlling the fueling), what engine operating mode its running in, and the other important settings that will tell you exactly what its doing (in cal$term) and then someone can tell EXACTLY why it might not be giving it full power/torque, etc. instead of assuming all the time like a blind-man that its your turbo.
similar to this: (cm870 example shown in this post)... ref: http://rawze.com/forums/uploads/202009/post_1744_1601314589_3612d1f8178317516535120edfc4ca40.png
I.E.> ACTUALLY TROUBLESHOOT IT INSTEAD OF GUESSING!!!
RE: Qsx15 turbo wastegate control valve? - Moffat - 11-01-2024
It is stock. Any altercations have been done only temporarily as a test. And no way to dyno a tractor with no pto. Also I’ve had cummins out to watch the computer while driving under load. They were the ones who suggested intake sensor. Had a third paty mechanic who was the cummins master at peterbuilt out. Suggested barometric pressure sensor and reflash thinking the file might have been corrupt on ecm. I’m assuming one of these mechanics watching the computer actually knew something about diagnosing their engine. Cummins also came out to diagnose the fueling and metering actuators. The closest test you can do on a tractor like this is hook a similar unit to a similar implement and compare. We have a 375hp 9280 with 855 cummins that would be very comparable in pulling power
RE: Qsx15 turbo wastegate control valve? - Moffat - 11-01-2024
I’ve also pressure tested the intake and got any leaks sealed up. With the waste gate hose clamped it doesn’t pull and more boost than without it clamped that’s why I’m leaning toward wastegate or waste gate controller issue now. But I can’t find any diagnostic or functionality check on the controller only the solenoids on it.
RE: Qsx15 turbo wastegate control valve? - Moffat - 11-01-2024
The regulator valve in question is p/n 3348688
RE: Qsx15 turbo wastegate control valve? - Rawze - 11-01-2024
(11-01-2024 )Moffat Wrote: It is stock. Any altercations have been done only temporarily as a test. And no way to dyno a tractor with no pto. Also I’ve had cummins out to watch the computer while driving under load. They were the ones who suggested intake sensor. Had a third paty mechanic who was the cummins master at peterbuilt out. Suggested barometric pressure sensor and reflash thinking the file might have been corrupt on ecm. I’m assuming one of these mechanics watching the computer actually knew something about diagnosing their engine. Cummins also came out to diagnose the fueling and metering actuators. The closest test you can do on a tractor like this is hook a similar unit to a similar implement and compare. We have a 375hp 9280 with 855 cummins that would be very comparable in pulling power
it is a mistake to put too much trust in those OEM techs and assuming they can tell you what its doing. They are blind as a bat!@!!, ... as they are not allowed to access it thru things like CT, and only use Insite or some other half.baked crap which is mostly useless with those kinds of issues.
5 MINUTES ON A TEST DRIVE WITH MY LAPTOP AND I COULD AT LEAST TELL YOU EXACTLY WHAT THAT COMPUTER WAS DOING ... WHY THE FUEL/POWER WAS NOT ALL THERE ... AND WHAT SIGNALS WERE CAUSING IT!!!. There are more than 150+ reasons that the ecm might hold back the fueling/power .... and the fuel-air-mix (your turbo) being only one of them.
(Page 54 in this document is what I am roughly referring to)...
REF: http://rawze.com/forums/showthread.php?tid=7677&pid=67395#pid67395
The 570's have many of those same settings to check. The names are just different (older standard), and some of it (like the AECD) is in RAM memory only on those things, but most all of it can be monitored.
How about someone calling back up those OEM blind-mice that are doing nothing but guessing.. and ask them some real questions that are related to the issues. Things like what operating mode(s) was it running in?.
... and what was the hex codes for commanding the 'CBL_Fuel_State?. What was the transition codes during hard acceleration and at max output?. Things like fueling quantities, .. what was the AECD state(s) that were active on it and what effect they were having on the engine output. Things like alterations to the fuel-air-mix, turbo speed vs. charge flow inputs, etc. monitoring, fueling, etc.etc.etc
I.E><<-- NONE OF THOSE BLIND-MAN MECHANICS AT THE STEALSERSh$ITS CAN TELL YOU ANY OF THAT BECAUSE THEY ARE NOT ALLOWED TO ACCESS THOSE THINGS!@!!!.. THE OEM PLACES ARE ABSOLUTELY NOT ALLOWED TO SEE WHAT IS ACTUALLY GOING ON INSIDE THAT THING (VIA CT) SOFTWARE... NOR HAVE THEY BEEN TRAINED TO PROPERLY TO DO SO!!!
i.e.> Read what I said above and do those things that can make a difference in how to find it instead of blindly trusting using a bunch of clueless, kept-in-the-dark blind mice mechanics at the trash-can stealers$its.
-- and has anyone pressurized the whole intake system, etc. and made sure there were no leaks?... and not just the CAC?. Anyone removed the exhaust behind the turbo to see if it picked up some boost level?... to see if the exhaust was restrictive somewhere unexpectedly?.
- Has anyone done any injector leakage tests on it?. ref: http://rawze.com/forums/showthread.php?tid=7747&pid=67948#pid67948
RE: Qsx15 turbo wastegate control valve? - Rawze - 11-01-2024
(11-01-2024 )Moffat Wrote: I’ve also pressure tested the intake and got any leaks sealed up. With the waste gate hose clamped it doesn’t pull and more boost than without it clamped that’s why I’m leaning toward wastegate or waste gate controller issue now. But I can’t find any diagnostic or functionality check on the controller only the solenoids on it.
register your enigne ser# on quickserv.com and get all the procedures, diag, etc. for troubleshooting that turbo/wastegate, etc... its free.
RE: Qsx15 turbo wastegate control valve? - Moffat - 11-01-2024
Yes I removed exhaust and tested. Also tested complete intake system. And I’ve checked all over on quickserve. Although I’m not an expert on it I’ve gone through most if not the whole service manual on the enginei have tried to follow the troubleshooting to the best of my ability. I just can’t find any additional information on that valve whether it controls the fueling or wastegate or what it’s actually doing. I’m thinking it’s not a part that was commonly used so they’re isn’t a whole pile of information on it. Only an ohm test for the electrical side of the valve which isn’t failing. That’s also the reason I’d like to just make this tractor identical to my others if it’s only the turbo and a tune away. It would make diagnosing a power issue more accurate when I could hop between two supposed identical tractors. When Cummins was out they did injector cutout test but it just tested front 3 cyl vs back 3 cyl. No bubble test but it idles smooth and doesn’t smoke mores than it should. I’d like to have a way to acces the information or get somebody who knows what they are actually looking at to watch the computer. It would make my life a lot easier. I’ve done a hours of reading but I can only dig so deep without any computer software and I don’t want to screw something up with nobody showing me what I’m reading in the ecm. Local Cummins closed down this year so they aren’t an option anymore either